The U.S. has been preparing for this moment since it first gathered in Stanford, California, five weeks ago to begin training camp. So unlike Italy manager Cesare Prandelli, who has brought up the weather at almost every opportunity over the last two weeks, U.S. manager Jurgen Klinsmann remained unconcerned.

"I think we are very well prepared for this climate here in Manaus," he said at Saturday's news conference. "It's similar to climates in CONCACAF or Central America, or even if you go to Florida and play in Miami. It's similar to what we experience here. I think we are very well prepared for tomorrow."

Tim Howard is more than capable of handling Portugal and helping the U.S. into the round of 16.

The Americans' ability to recover from their opening game against Ghana is another factor to consider. The U.S. were forced to defend for the vast majority of the encounter, and as a consequence put in an immense amount of energy into the match. But U.S. goalkeeper Tim Howard insisted that recovery process since that night in Natal has gone well, and that the Americans should be ready to go against Portugal.

"The team seems to have trained really well the last couple of days," he said. "We got a lot of sleep after the first game when we arrived back in Sao Paulo. We've not done anything different to prepare for the heat. I think we're fit and we're conditioned. As long as we get good sleep and stay hydrated, we should be fine."

The forecast calls for an 80 percent chance of rain on Sunday, and it's debatable as to how much that might benefit the U.S. side. While the precipitation might serve to cool down the temperatures to a degree, it might also have the effect of turning the much-maligned surface at the Estadio Amazonas into something resembling quicksand, which could create a bit of fatigue down the road.

The U.S. can think about those effects later, however. For now, the focus is on the match at hand against a difficult opponent.